NEW YORK (AP) — Poor Rusalka! The water nymph heroine of Antonin Dvorak's best-known opera never stands a chance against the witch Jezibaba — especially as played to the hilt by the powerhouse mezzo-soprano Jamie Barton.

"She's one of the few characters I've encountered who is truly evil," Barton said in an interview at the Metropolitan Opera, where she is performing in the new Mary Zimmerman production. "I don't really find redeeming qualities. But I do find interesting qualities."

"Rusalka," starring soprano Kristine Opolais in the title role, will be broadcast live in HD to movie theaters on Saturday.

The opera, a variation on "The Little Mermaid" without the Disney happy ending, tells of Rusalka's longing to become human. Jezibaba agrees to engineer the transformation but warns she will be unable to speak and that if she fails at finding true love, she will be damned and the object of her affections will die.

When Jezibaba first appears, clothed like a Victorian matron with an ominous spiderweb pattern on her dress, "she's got the mask on, saying yes, of course I'll help you, but you have to agree to these impossible terms," Barton said.

"There's a lot of humor in the first act, and what she has going for her in spades is truth," Barton said. "When Rusalka says, 'I want to be human,' my response is 'Are you really going to stoop that low?' I don't think Jezibaba has a very high opinion of humans. One of the things she says is, 'A human is not a human until he has wet his hand in another's blood.' That's a really dark line, but if you look quite honestly at the state of the world now ...

"By the time you see her in the third act all pretense has slipped away," Barton said, "and the moment Rusalka throws up any sort of resistance, she gets nasty."

Throughout, Barton matches her prodigious vocal abilities from high notes to low (including a blood-curdling cackle for her final exit) with a restless physicality that perfectly conveys Jezibaba's diabolical machinations. Critic James Jorden wrote in the New York Observer that "lurching, heaving and writhing nonstop, she looked as if she might any moment explode out of sheer malevolence."

THAT LUNAR TUNE

Before Rusalka loses her voice, Opolais gets to sing the most famous aria in the score, the wistful "Song to the Moon." It's a favorite recital item for sopranos and is often heard in movies, most notably "Driving Miss Daisy."

"Rusalka," which premiered in Prague in 1901, is the only one of the Czech composer's 10 operas to be performed with any regularity outside his native country. It first reached the Met in 1993, with Gabriela Benackova as the nymph, a role that later became a favorite of Renee Fleming.

WHERE TO SEE IT

The HD broadcast of "Rusalka," conducted by Mark Elder and also starring tenor Brandon Jovanovich as the prince who is fatally attracted to Rusalka, soprano Katarina Dalayman as her rival, the Foreign Princess, and bass-baritone Eric Owens as her father, will be shown starting at 12:55 p.m. Eastern on Saturday. A list of theaters can be found at the Met's website: metopera.org/hd.

In the U.S., it will be repeated on Wednesday, March 1, at 6:30 p.m. local time.